Self-propelled vibratory compactor



Oct. 27, 1964 J. E. KEPPLER 3,153,993

SELF-PROPELLED VIBRATORY COMPACTOR Filed Jan. 12, 1962 4 Sheets-Sheet l INVENTOR.

JOHN E. KEPPLER Oct. 27, 1964 J. E. KEPPLER SELF-PROPELLED VIBRATORY COMPACTOR 4 Sheets-Sheet 4 Filed Jan. 12, 1962 INVENTOR.

JOHN E. KEPPLER BY 3M, 7mm, a m

United States Patent tion of Texas Filed Jan. 12, 1962, Ser. No. 165,926 4 Claims. (Cl. 94-50) This invention relates to vibratory compacting rollers and more specifically to each-resonant vibratory rollers of the self-propelled type used primarily for compacting road surfacing materials. Earth-resonant vibratory rollers are unusually effective in compacting ea rth materials such as artificially occur in fills, dams, and road surfacing operations. The rate of compaction effected by vibratory rollers is rapid, and for even compaction it is necessary for the roller to apply its compaction forces to the underlying material evenly across its width to obtain the most the efficient results. 7

It is the object of the present invention to provide a selfpropelled earth-resonant vibratory roller in which the compaction of the roller is at all times gravitationally controlled, free of transverse moments tending to produce irregularities in compaction across its working face.

It is a further object of the present invention to provide in a self-propelled earth-resonant vibratory roller, a traction axle freely pivoted to avoid the application of undue forces to the vibratory roller by reason of irregularities in the working surface underlying the traction axle.

It is yet a further object of the present invention to provide a highly efiicient earth-resonant vibratory roller for rapid and efiicient compaction of earth and road surfacing materials.

The present mac iine employs a forward compaction drum and a trailing traction axle provided with pneumatic tires. The traction axle is independently driven by an internal combustion engine under control of the operator at the desired speed and direction, while the cornpaction roller is vibrated from a separate drive train leading to an independent power source.

The compaction roller of the present machine is similar to that disclosed in pending application Serial No. 810,363 filed by John E. Martin, May 1, 1959, now Patent No. 3,653,157 and assigned to the assignee of the present application. The roller is provided at either end with stub axles carried by journals mounted on the frame of the machine. The stub axles are hollow and carry internally a continuous shaft which extends from one end of the roller to the other. The shaft is journaled in roller hearings on the roller, concentrically therewith, and is provided with eccentric weights, one adjacent each end of the roller. The central shaft extends outward of one of the stub axles and is provided with a drive sheave for rotating the same and developing harmonic vibratory forces at a frequency determined by the rate of rotation of the shaft. It will, therefore, be understood that the compaction roller is freely mounted for rotation in response to movement of the frame, While at the same time vibratory oscillations may be developed in the roller through its coupling to the vibrator shaft mounted centrally in it. An independent vibratory drive engine is provided which may be conveniently controlled to vibrate the underlying earth structure at its naturally resonant frequency to obtain super-normal compaction as the roller is traversed across the earth structure.

In the present invention, the compaction roller is mounted on the frame of the machine by a flexible assembly to minimize the vibratory forces applied to the machine from the roller. As will appear below, the vibratory assembly internal of the compaction roller is belt driven from an independent engine which in turn is de- 3,153,993 Patented Got. 27, 1964 ice coupled from the frame of the machine by flexible mounts and connected by a flexible drive to the drive sheave.

The operators position, and the machine controls which are grouped therearound, are located aft of the compaction drive engine and forward of the independent traction engine which powers the trailing traction axle.

In order to maintain uniform operation of the compaction roller in its vibratory engagement with earth materials, independent of the transverse inclination of the traction axle, special mounting means have been provided to permit the traction axle to tilt quite freely transversely of the machine while constraining its position in other planes substantially to a predetermined orientation to the frame of the machine.

The propelling engine is located on the frame directly over the rear axle for maximum traction, and is coupled thereto through a suitable power delivery train.

The machine in the present invention will be further understood with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation of the machine,

FIGURE 2 is a top plan view of the machine shown in FIGURE 1,

FIGURE 3 is a transverse View of a portion of the vibratory roller showing a stub axle and the driving end of the oscillatory shaft assembly.

FIGURE 4 is an exploded view of the portion of the traction axle mount which is attached to the axle, and

FIGURE 5 is an exploded view of the upper part of the traction axle mount which is attached to the frame of the machine. 7

The main frame or chassis of the roller of the present invention is of vertically offset construction in which the forward portion underlies the roller axle and the rear portion overlies the traction axle. The vibrator driving englue is mounted on the lower portion of the chassis aft of the roller. The traction axle drive engine is mounted at the rear of the chassis directly over the drive axle. On the aft section of the chassis, but forward of the drive engine, is provided an operators position to situate the driver at a high level for good visibility and at the same time to provide convenient access to operating controls for both engines. As shown in FIGURE 1, the forward portion of the main chassis comprises longitudinally extending side members 2, 2 of welded box girder construction. At their aft ends, the side members carry welded vertical extensions 3, 3. Forward cross member 4 connects the front ends of side members 2, 2 and is welded therebetween. A second cross member 5 is welded between the upper ends of vertical members 3.

The upper rear portion of the chassis is formed by a pair of spaced longitudinal box girder members 6, 6 Welded to the rear surface of transverse member 5-. The rear of the chassis is formed by a vertical plate 7 attached to the aft end of frame members 6,6. Additionally, the lower extension of plate 7 is connected by gusset plates 8, 8 to the frame members 6, 6. At the lowermost end of plate 7 is welded a channel shaped member 9 which serves as a rear bumper for the roller.

Above each of the frame members 6, 6 are provided sheet metal fenders 10, 10 extending to each side of the machine to provide an operators platform. Fenders 10 are additionally supported by gussets 10a welded thereto and to vertical members 3.

The internal combustion vibratory drive engine is supported on the lower portion of the chassis by a cross member 11 welded between the side members 2, 2 aft of the compaction roller. The engine 110 is'suppo'rt'ed on bed plates 12 overlying cross member 11 and connected therewith on either side byguss'e't plates 13. Engine 110 drives sheave 29 on shaft 28 which is journaled at 18, 18.

3 Journals 18 are supported on channel-shaped member 15, which is supported above cross member 11 by vertical spacers 16 welded therebetween.

Engine 111 is coupled to shaft 28 by a splined con necting shaft 27 provided at each end with a universal coupling 27a.

The engine is resiliently supported from bed plates 12 by rubber mounts 45 connected between angles 4-6 carried by the bed plates and mounting plates 44 integral with engine 110. The resilient mounting of the vibratory drive engine, together with the flexible connection of power transmission provided by elements 27 and 27a, relieves the engine structure from vibration of the main frame during compaction operations, as will further appear below.

Roller 20, as well as the vibratory drive engine, is covered by an overlying hood member 19 which is apertured to provide access to engine 110 and its drive connections.

Roller 20 is provided with end plates 14 which are centrally apertured to receive similar axle assemblies on each side of the drum. The vibratory shaft drive assembly is representative, and is shown in section in FIG- URE 3. Here, end plate 14 of roller 20 is bolted to a hollow stub axle 24 which is freely journaled relative to forging 33, one of which is provided at either side of the roller, resiliently mounted on side members 2, 2. Threaded into forging 33 is hub 34 which is locked in position by set screw 35. Internally pressed in hub 34 are sleeve bearings 99 which engage and journal the outer surface of hollow stub axle 24.

As best shown in FIGURE 2, suspension forgings 33 are resiliently supported forward and aft on both sides by rubber shock elements 36 bonded on their outer faces and connecting to support brackets 38 welded to frame member 2. This assembly permits vibration of the stub shafts 24 on either side of the roller drum with only limited vibration transmission to the chassis frame members 2, 2. At either end, the freedom of motion of forgings 33 is restrained by rubber bumpers 43 spaced slightly therefrom and supported from side member 2 by bracket 43a.

The drum is vibrated by means of rotatable shaft 21 which passes completely through the axis of the roller and is enclosed by hollow stub shafts 24 at either side.

Shaft 21 carries at one end a drive sheave 26, as shown in FIGURE 3. This sheave is connected by belts 39 to the main drive sheave 29 coupled to the vibratory drive engine 110. Belt tension is maintained by idler pulley 31 adjustably attached to a vertical member 32 welded appropriately to frame member 2. The vibrator drive is covered by a belt guard which is supported on the longitudinal side frame member 2.

Vibrator shaft 21 carries adjacent each end plate 14 of the roller, eccentric weights 22 which are positioned in alignment on shaft 21 and develop vibratory forces as the shaft is rotated. Shaft 21, as shown in FIGURE 3, is journaled by the roller bearing 23 received as shown in stub axle 24. Bearing 23 is retained in the stub axle by member 98 bolted to stub axle 24. As shown in the drawings, the hubs 34 are retained on the stub shafts 24- by thrust rings 10%, lock washers 101, and lock nuts m2. Lubricant is retained and dirt is sealed out of the bushings by means of hubcap 1M and seal 105.

At the opposite end of shaft 21 from that shown in FIGURE 3, an entirely similar construction is employed save for the fact that shaft 21 terminates at a position adjacent to end of lock nut 102, and hub cap 1% encloses the entire bearing assembly overlying the end of the shaft 21.

Angle scraper bars 95 and 96 extend across the face of roller 26) to detach adhered material. Scraper 95 is bolted to front frame member 4 by means of the attaching angle brackets 97 with slotted holes to permit adjustment relative to roller 20. Scraper 96 is adjustably bolted to the under side of members 2, 2 and provided with an adjustment connection bracket 78 for the purpose of setting its desired position relative to the roller surface.

The rear traction steering type axle 47 is mounted below longitudinal members 6. It is provided with pneumatic tires 48, steerable about king pins 49. This axle assembly is provided with an internal differential gearing arrangement and the two drive shafts (not shown), coupled by universal joint members to the wheel hubs. The construction of these components of the invention is conventional. The driving input to the axle is delivered through universally mounted and conventionally splined propeller shaft 72 which is driven from a chain drive assembly box 71 of conventional construction mounted centrally on the transverse frame member 5. The upper sprocket drive shaft of the chain drive box 71 is also powered from a universally mounted splined shaft assembly 70 coupled to the output shaft of gear transmission 69. A parking brake assembly 17 is also provided between drive shaft 7t and gear box 69. Transmission 69 is a four speed gear shift in which the gear selection can be made by shift lever 74 by the operator. Power input to gear transmission 69 is taken from gear mechanism as which is a hydraulically operated clutch forward and reverse gear transmission operable by lever 73 through linkage from control handle 75. The reversing gear mechanism 63 is powered from torque converter 67 provided with power from engine 82.

All the power drive mechanisms described between drop box 71 and engine 32, and including the latter, are mounted conventionally on longitudinal frame members 5, 6.

Lever 75 operates pivoted on cross shaft 76 and is attached through connecting link 73 to lever 73 of the reverse gear mechanism. In the vertical position shown, both hydraulically operated clutches in transmission 68 are disengaged in neutral position. Initial movement of lever 75 in the direction of roller travel desired causes one or the other of the hydraulic clutches appropriately to be engaged to drive the roller in the desired direction. Further movement of lever 75 causes lever 79 of the transmission 63 to be actuated to open the main throttle of engine 32 by lever 84) through connecting rod 81. Thus, the direction of travel as Well as the speed of travel is controlled by operating member 75 to engage the proper gearing and bring the traction drive engine 82 above idling speed to the desired operating speed. For a selected engine speed, the vehicle speed may be any of four values as determined by the gear change transmission 69 under selection of shift lever 74.

Also shown at FIGURE 2 is brake pedal 112 connected to master hydraulic cylinder 84 by push rod 113. Master cylinder 84 is bolted to fender It by angle bracket 85, and lines and hoses connecting to brakes of the main drive traction axle are provided for conventional operation, but are not shown in the drawings.

The operators position is provided with seat 91) of conventional construction carried by deck In. In front of the operator is provided steering wheel 59 coupled to steering reduction gear 6Q, pitman arm 61, connecting rod 62, idler arm 63, connecting rod 64, steering arm 65, and tie rod 6d. The latter tie rod is pivotally connected to the outer ends of the steering knuckle housing 114 which is free to oscillate about the king pins 49. It will be evident that the operation of the steering wheel 59 will be effective to swing the wheels 43 about the king pins 49 in such a manner as to effectively steer the machine during operation.

In the operation of the roller, particularly in filling operations where close grading is not practiced, it is most important that roller 2% be gravitationally engaged with the underlying surface free of application of rotational moments above an axis longitudinal of the machine. For this purpose it is essential that the traction drive axle swing about an axis longitudinally of the machine while being restrained for other displacements. This operation is secured by the provision of a unique mounting arrangement in which traction axle 47 is connected to the over lying frame members 6, 6. As shown in FIGURES 4 and 5 in exploded view, and in FlGURE l in assembled position, mounting pads 57 of axle 47 are bolted to overlying mount members 56 of FIGURE 4. This fitting rigidly positions cylindrical members 52 centrally of the axle in an overlying fore and aft spaced arrangement. A double tapered rubber bushing 51 is passed into each cylindrical member 52 and receives, internally, pins 54 (FIGURE 5) whose extremities are engaged in apertures 55a of bars 55 and retained therein by bolt and washer assemblies 54a.

The spaced bars 55 are Welded to overlying plate 58 which is bolted to the lower surfaces of each of longitudinal frame members 6, 6.

The main support of bushings 51 is provided centrally of their length by the enhanced diameter engaging the middle of cylinders 52. The traction axle mounting assembly thereby permits pivoting of the traction axle about a longitudinal axis of the vehicle bisecting cylindrical bushings 52 and thus permits compaction operation independent of the lateral inclination of drive axle 47.

In compaction operations, therefore, the driver has complete and independent control of the speed and direction of the roller as determined by the drive train between engine 82 and traction axle 47. At the same time, vibratory drive engine 110 may be controlled by throttle lever 83 forward of the operating position connected to the throttle of engine 110 by a flexible control cable 85. Moving lever 83 upward or downward as indicated by the arrows in FIGURE 1 causes rapid closing and opening of the throttle through a toggle linkage. Rotating control member 86 causes fine adjustment of the control cable by a threaded rod attachment. Therefore, quick opening and closing the throttle is provided with precise adjustment for resonating compaction frequency by engine speed.

The operator is also provided with a clutch control lever 111 connected to clutch operator 87 for vibratory drive engine clutch 88. A flexible control cable 89, pivotally attached at its end to the clutch lever permits the operator to engage or disengage engine 110 from the vibrator drive shaft assembly 27 while seated in the operators seat 90.

In order to ascertain the amplitude of vibration which indicates when earth-resonance is being obtained, a vibration transducer 95 is mounted on the main frame at cross member 11. The amplitude of vibration of the frame is converted into an electrical signal by means of an inertia or weight loaded electrical transducer, which may be an electromagnetic generator responsive to linear motion, or a piezo crystal type unit. This output signal is delivered through electric transmission line 117 to an indicating meter 118 positioned forward of the operator. Thus, the operator, by adjustment of the operating speed of engine 110 by control 86, is enabled to maximize the oscillation amplitude as indicated by meter 118 and immediately obtain and maintain resonant compaction in operation of the machine.

It will be understood that the device of the present invention is not limited to the specific details here disclosed, and that the scope of the invention is to be construed with reference to the appended claims:

I claim:

1. A self-propelled vibratory compactor comprising a rigid chassis, a roller freely journaled at one end of the chassis and coupled resiliently thereto, vibration generation means rotatably mounted within said roller, a traction drive axle at the other end of the chassis, said drive axle comprising a pair of steerable drive wheels, a pair of cylindrical members carried transversely by the chassis and longitudinally spaced thereof over the drive axle, annular resilient members surrounding the cylindrical members, and means engaging the periphery of the resilient members rigidly positioned on the drive axle to rockably mount the axle centrally of the chassis, an adjustable speed engine coupled to the vibration generation means for driving the same at an earth resonant frequency, a second engine independent of said first engine connectable in driving relation to the traction drive axle, an operating position intermediate of the chassis, and engine speed control means for both engines adjacent the operato-rs position.

2. A compactor define-d in claim 1 wherein the means engaging the periphery of the annular resilient members are also annular and said resilient members are tapered toward either end to provide static engagement with the annular means only centrally thereof.

3. A self-propelled vibratory compactor comprising a rigid chassis having a first horizontal end section and a second horizontal end section elevated relative to the first section, a freely journaled roller resiliently mounted in the first end section, eccentric means for Vibrating said roller; first motor means carried on the chassis for driving the eccentric means at an earth resonant frequency; a traction drive axle assembly positioned under the second section comprising a pair of traction wheels steerably mounted about substantially vertical axes; second motor means; transmission means connecting the second motor means to the traction wheels; means for rockably connecting the drive axis to the overlying chassis section consisting of a pair of horizontal annular cylindrical resilient bushing elements longitudinally spaced of the chassis, positioned centrally thereof, and fore and aft of the drive axle axis; and rigid means connecting the inner and outer surfaces of each bushing respectively to the chassis and the axle assembly, whereby the roller will at all times freely conform to the underlying surface independent of angularity of the drive axle assembly in its vertical plane transverse with respect to the chassis.

4. The compactor of claim 3 wherein the resilient bushing elements are tapered at each end within the rigid means to provide engagement therewith only centrally of one of the bushing surfaces.

References Cited by the Examiner UNITED STATES PATENTS 2,086,557 7/37 Kaptuller 28011.28 2,197,183 4/40 Keeler 9450 2,199,649 5/40 Poulter 94-50 2,230,317 2/41 Zettelmeyer 9450 2,582,775 1/52 Giacosa 267-66 2,812,696 11/57 Henry 9448 2,873,656 2/59 Anderson 94-50 2,897,734 8/59 Bodine 9422 2,907,579 10/59 Masser 267-52 2,942,870 6/60 Balding 267-52 3,029,715 4/ 62 Bowen 9446 3,047,307 7/62 Beyerstedt 280-111 JACOB L. NACKENOFF, Primary Examiner. 

1. A SELF-PROPELLED VIBRATORY COMPACTOR COMPRISING A RIGID CHASSIS, A ROLLER FREELY JOURNALED AT ONE END OF THE CHASSIS AND COUPLED RESILIENTLY THERETO, VIBRATION GENERATION MEANS ROTATABLY MOUNTED WITHIN SAID ROLLER, A TRACTION DRIVE AXLE AT THE OTHER END OF THE CHASSIS, SAID DRIVE AXLE COMPRISING A PAIR OF STEERABLE DRIVE WHEELS, A PAIR OF CYLINDRICAL MEMBERS CARRIED TRANSVERSELY BY THE CHASSIS AND LONGITUDINALLY SPACED THEREOF OVER THE DRIVE AXLE, ANNULAR RESILIENT MEMBERS SURROUNDING THE CYLINDRICAL MEMBERS, AND MEANS ENGAGING THE PERIPHERY OF THE RESILIENT MEMBERS RIGIDLY POSITIONED ON THE DRIVE AXLE TO ROCKABLY MOUNT THE AXLE CENTRALLY OF THE CHASSIS, AN ADJUSTABLE SPEED ENGINE COUPLED TO THE VIBRATION GENERATION MEANS FOR DRIVING THE SAME AT AN EARTH RESONANT FREQUENCY, A SECOND ENGINE INDEPENDENT OF SAID FIRST ENGINE CONNECTABLE IN DRIVING RELATION TO THE TRACTION DRIVE AXLE, AN OPERATING POSITION INTERMEDIATE OF THE CHASSIS, AND ENGINE SPEED CONTROL MEANS FOR BOTH ENGINES ADJACENT THE OPERATOR''S POSITION. 